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-   -   Which is faster carb or Fuel injection? (https://classracer.com/classforum/showthread.php?t=48500)

Ed Wright 07-24-2013 07:15 PM

Re: Which is faster carb or Fuel injection?
 
Guys, the carb guys aren't going to believe you by they think there is magic in that ECU. LOL

Btw, that small TB is restrictor. It flows less air that a QJet. My friends with 350"s & carbs often run well past 8500 in the lights, some way past. Dave Layer, when I ordered my heads, told me a 350" would all done by 8200 RPM, of course he was correct. Smart man.

Joe DeMarzo 07-24-2013 09:45 PM

Re: Which is faster carb or Fuel injection?
 
Barry rumor has it that neither of us is the fastest H/SA in D-1 let alone at Indy. I am going to take a pass been a rough year. My ego can't take losing hahahaha. My money is on you if you go in H/SA. That is why I am looking for a soft EFI combo.

Tony Curcio 07-24-2013 11:05 PM

Re: Which is faster carb or Fuel injection?
 
I'm gonna take a stab at this. The Third Gen Camaros mentioned above have a manifold with relatively long runners, which will make more power down low, and perhaps explains why you observed a harder launch.
Q-Jet manifold that I assume Frank and Lee refer to have much shorter runners, and should make peak power at a higher RPM, which probably accounts for the higher peak HP observed.
If the comparison was made with identical manifolds and the same total area throttle body/throttle blades, and fuel curves both optimized to whatever extent possible, I'll argue that the FI has superior atomization, and should make a little more power at every increment.

Signman 07-25-2013 09:14 AM

Re: Which is faster carb or Fuel injection?
 
[QUOTE= That is why I am looking for a soft EFI combo.[/QUOTE]

Get a new Camaro or Mustang.
Or call Billy.

Signman 07-25-2013 09:23 AM

Re: Which is faster carb or Fuel injection?
 
[QUOTE=
If the comparison was made with identical manifolds and the same total area throttle body/throttle blades, and fuel curves both optimized to whatever extent possible, I'll argue that the FI has superior atomization, and should make a little more power at every increment.[/QUOTE]

Let's take an look at a ringer in the Mopar DragPak engine with the tall single plane and throttle body on top. Easily replaced with a carb. If the throttle body was flowed, a really good Holley was assembled to match, have a feeling that there would be little to nothing.

Don't think there is any way to compare EFI to Carb in a stocker apples to apples. If you look at the potential of the combination with it's HP rating then you have something to study. Not being a dedicated student it appears to be a new car or a slow car.

Michael Beard 07-25-2013 12:27 PM

Re: Which is faster carb or Fuel injection?
 
Quote:

Let's take an look at a ringer in the Mopar DragPak engine with the tall single plane and throttle body on top. Easily replaced with a carb. If the throttle body was flowed, a really good Holley was assembled to match, have a feeling that there would be little to nothing.

Don't think there is any way to compare EFI to Carb in a stocker apples to apples.
Correct. My 5.9L DragPak uses the identical M1 single plane manifold that my 360 Magnum crate motor (w/ 750 Holley) had. They come with the bosses to be drilled for injectors. That being said, simply swapping carb vs EFI, even adjusting jetting/tuneups, is not as apples to apples as one would think. There are other variables involved in optimization for each.

Lee Valentine 07-25-2013 01:12 PM

Re: Which is faster carb or Fuel injection?
 
Joe if you find a soft EFI combo call me!

Stock726 07-25-2013 02:56 PM

Re: Which is faster carb or Fuel injection?
 
Quote:

Originally Posted by Lee Valentine (Post 392063)
Joe, on Bryan's 305 the carbureted combo made 20 more horsepower than the F.I. and made power at a higher rpm. The F.I. combo makes more torque and has a flatter torque curve. run at the same weight the carb is faster.

Hot Rod mag did a comparison test about a year or so ago using an FI LS1. They swapped on the Edelbrock LS1 4-barrel manifold/carb and made more peak HP in every test. The torque curve was a lot peakier however. Of course the EFI system is infintely more tunable, so there's that... The results really surprised me, I thought the FI would be more efficient by design?

Kegracing 07-25-2013 07:41 PM

Re: Which is faster carb or Fuel injection?
 
Some really interesting results and good things that make you think here... which is why I replied to this post to start with.
I will have to try to find the Hot Rod article. Same type of apples to apples that Michael is talking about. My question, is the throttle body truely the same cfm as the carb?
Just hard to understand how on same cfm of air flow, the carb would make more HP, with the tuning ability of the FI cylinder to cylinder. NOT arguing, just trying to understand.
But then again, I have raced for years, and racing in the summer in TX... :) Never been very smart!

Ken

keith ohanesian 07-25-2013 11:54 PM

Re: Which is faster carb or Fuel injection?
 
Lee you guys ran one 10 years ago. It's light and can be FAST.


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